Semiconductor device with surrounding bump metallization and method therefor

Abstract

A method of manufacturing a semiconductor device is provided. The method includes forming a first non-conductive layer over a top side a semiconductor die and patterning the first non-conductive layer to form an opening exposing a top surface of a bond of the semiconductor die. A metal trace of a redistribution layer is formed over a portion of the first non-conductive layer and exposed top surface of the bond pad. A surrounding bump metallization (SBM) structure is formed on a portion of the metal trace. The SBM structure includes a plurality of vertical metal wall segments surrounding a central opening.

What is claimed is: 
     
         1 . A method comprising:
 forming a first non-conductive layer over a top side a semiconductor die;   patterning the first non-conductive layer to form an opening exposing a top surface of a bond pad of the semiconductor die;   forming a metal trace of a redistribution layer (RDL) over a portion of the first non-conductive layer and exposed top surface of the bond pad; and   forming a surrounding bump metallization (SBM) structure on a portion of the metal trace, the SBM structure including a plurality of vertical metal wall segments surrounding a central opening.   
     
     
         2 . The method of  claim 1 , further comprising placing a ball connector into the central opening of the SBM structure such that the plurality of vertical metal wall segments substantially surround the ball connector. 
     
     
         3 . The method of  claim 2 , wherein a height dimension of the plurality of vertical metal wall segments is approximately in a range of 40% to 60% of a largest diameter of the ball connector. 
     
     
         4 . The method of  claim 2 , further comprising reflowing the ball connector such that conductive material of the ball connector wets to the entire inner sidewalls of the plurality of vertical metal wall segments of the SBM. 
     
     
         5 . The method of  claim 1 , wherein the each of the vertical metal wall segments of plurality of vertical metal wall segments is separated from a neighboring vertical metal wall segment by a respective gap, the gap having a predetermined lateral dimension. 
     
     
         6 . The method of  claim 5 , wherein the predetermined lateral dimension of the gap is substantially 10 microns or greater. 
     
     
         7 . The method of  claim 5 , wherein the gap extends vertically from the portion of the metal trace to a top of the plurality of vertical metal wall segments. 
     
     
         8 . The method of  claim 1 , wherein forming the SBM structure includes forming the plurality of vertical metal wall segments as electroplated copper pillars. 
     
     
         9 . The method of  claim 1 , further comprising:
 forming a second non-conductive layer over the first non-conductive layer and exposed portions of the metal trace; and   patterning the second non-conductive layer such that a top surface of the metal trace is exposed in the central opening of the SBM structure.   
     
     
         10 . A semiconductor device comprising:
 a first non-conductive layer over a top side a semiconductor die, an opening in the first non-conductive layer exposes a top surface of a bond pad of the semiconductor die;   a metal trace of a redistribution layer formed over a portion of the first non-conductive layer and exposed top surface of the bond pad; and   a surrounding bump metallization (SBM) structure formed on a portion of the metal trace, the SBM structure including a plurality of vertical metal wall segments surrounding a central opening.   
     
     
         11 . The semiconductor device of  claim 10 , wherein the plurality of vertical metal wall segments of the SBM structure are formed as electroplated copper pillars. 
     
     
         12 . The semiconductor device of  claim 10 , wherein a height dimension of the plurality of vertical metal wall segments is substantially in a range of 40% to 60% of a horizontal width or diameter of the central opening. 
     
     
         13 . The semiconductor device of  claim 10 , further comprising a reflowed ball connector surrounded by the plurality of vertical metal wall segments such that conductive material of the ball connector is wetted to the inner sidewalls of the plurality of vertical metal wall segments and to the portion of the metal trace. 
     
     
         14 . The semiconductor device of  claim 13 , wherein a height dimension of the plurality of vertical metal wall segments is at least 50% of a maximum height dimension of the reflowed ball connector. 
     
     
         15 . The semiconductor device of  claim 10 , wherein each vertical metal wall segment of the plurality of vertical metal wall segments is separated from a neighboring vertical wall segment by way of a gap, the gap having a predetermined lateral dimension. 
     
     
         16 . A method comprising:
 forming a first non-conductive layer over a top side a semiconductor die;   patterning the first non-conductive layer to form an opening exposing a top surface of a bond pad of the semiconductor die;   forming a metal trace of a redistribution layer (RDL) over a portion of the first non-conductive layer and exposed top surface of the bond pad;   forming a surrounding bump metallization (SBM) structure on a portion of the metal trace, the SBM structure including a plurality of vertical metal wall segments surrounding a central opening, each vertical metal wall segment separated from a neighboring vertical wall segment by way of a vertical gap;   forming a second non-conductive layer over the first non-conductive layer and exposed portions of the metal trace; and   patterning the second non-conductive layer such that a top surface of the metal trace is exposed in the central opening of the SBM structure.   
     
     
         17 . The method of  claim 16 , further comprising placing a ball connector into the central opening of the SBM structure such that the plurality of vertical metal wall segments substantially surround the ball connector. 
     
     
         18 . The method of  claim 17 , further comprising reflowing the ball connector such that conductive material of the ball connector wets to the entire inner sidewalls of the plurality of vertical metal wall segments of the SBM structure and to the portion of the metal trace. 
     
     
         19 . The method of  claim 16 , wherein the vertical gap is formed having a predetermined lateral dimension, the predetermined lateral dimension substantially 10 microns or greater. 
     
     
         20 . The method of  claim 16 , wherein the plurality of vertical metal wall segments of the SBM structure are formed as electroplated copper pillars.